It seems that every time I look at someone else’s vision of how an inswinger must have looked, the machine is invariably striking a pose with it’s limbs showing dramatic amounts of rotation and, presumably, extra long draw lengths. This cool painting by Mr. Dominic Andrews shows what I’m getting at:

Have they never heard of stacking? The leverage angle between the bowstring and the limb becomes so nearly like a straight line it’s just not possible to pull it back any more. The springs are at maximum strain just when there is minimal draw back power to get them that way. There is a fundamental illogic about that arrangement. Anyway, Firefly wasn’t having any of this over-rotated hype. A short, intense, 45 degrees of limb rotation is where she found her power. I’ve heard the theories about how, with inswingers, long draw lengths and big rotations are better for throwing heavier objects. Maybe so, but there didn’t seem to be anything to it when Firefly was set up that way. Of course, Pumkin Chunkin ain’t exactly her forte.

I don’t always believe things just because mathematicians tell me they are true. Real world modelling has to count for something too. Maybe the math isn’t big enough. Of course, in fairness, maybe the modelling isn’t big enough either. Be that as it may, with Phoenix, I’m sticking to Firefly’s proven strategy for nice flat trajectories with Dura bolts: 45 degree limb rotation with an extra-extra taut resting bowstring, along with all the rotational pre-tension that implies. Locking in a couple of tons of linear stretching first, makes an excellent foundation for all the rotational stuff you are going to have to spend so much time foolin’ with, if you want to birth a balanced and powerful machine.

And if that all sounds a little bit serious, that’s because it is. (Rant alert) There is just too much work in this hobby to go down any more fruitless paths. If someone from the school of super-duper rotations wants to show us how to shoot an authentically weighted Dura Europos bolt a thousand yards from an actual machine (as Firefly has done), then we are all ears. In the meantime, my experience with Firefly (here we go again) warns that the stacking from big rotations would require a low rotational pre-tension to achieve full draw, which causes the bowstring to be loose when in the just fired, at rest position. This lack of tension in a resting bowstring is coincidental with sluggish velocities — not at all the thing after so much work is put into dreamin’ big.